1. Field of the Invention
This invention relates to a bag formed from heat shrinkable. thermoplastic film. In particular, this invention relates to a bag formed from thermoplastic film wherein the products packaged are food items and the bag is provided with an "easy-open" means.
2. Description of the Related Art
Food and other items are frequently packaged for retail purposes in shrinkable film that is then shrunk around the good. The film may initially be in the form of a bag in which even the bag is open at one end to permit the insertion of the goods or a product and is then sealed and shrunk around the product. It is often desirable to be able to provide the bag with an easy opening means, with a surface area upon which a label or printed matter may be placed, and with means for hanging the bag if that is desired.
Representative bags and containers employing shrink film features are found in, for example, U.S. Pat. No. 3,516,537 issued to Robert L. Dreyfus et al wherein is disclosed a package in which a plastic container having shrunken film walls and a product in the container is constructed so that film walls extending beyond the closure seal of the package form a flange section or skirt which is provide with a notch for the purpose of providing a tear Lab. In U.S. Pat. No. 4,249,659 issued to Henry G. Schirmer there is disclosed a bag and method of producing the bag by forming a pocket in a central portion of a sheet of wrapping material, which may be shrinkable thermoplastic film, placing a product within the pocket, folding the flat portions of the film into face-to-face contact and bonding the flat or flange portions together. In U.S. Pat. No. 4,000,325 issued to Gad A. Rausing here is disclosed a pressurized plastic container formed with transverse seals with a flattened area between the sealing zones. U.S. Pat. No. 3,641,732 issued to Masaaki Fujio discloses a bag in which a product is enclosed in plastic film which is heat shrinkable and which provides a tear tab protruding sideways from the bag. Another bag, shown in a patent to the same inventor, is disclosed in U.S. Pat. No. 3,679,048. In U.S. Pat. No. 3,889,870 issued to Hugo Bender a welded bag of stretched polyester film is shown in which the edge region of the bottom weld is post-stretched.
In U.S. Pat. No. 3,140,815 issued to John D. Majeskey a thermoplastic heat sealed bag is disclosed having heavily heat sealed tear and tie strip over a line of tear perforations. The tear strip panel must be permanently sealed at one end so that it may perform its function as a tie strip for resealing the bag. U.S. Pat. No. 3,391,851 discloses a tear tab which is adhesively sealed over a perforation on a heat shrunk container. Likewise, U.S. Pat. No. 3,175,752 issued to G. C. Stabenow discloses another form of adhesively attached tear tab on a heat shrinkable container. Canadian Patent No. 1,287,309 issued to Steven L. Fuller discloses a film bag with perforations sealed with a tear tab attached to the bag using a pressure sensitive adhesive.
In U.S. Pat. No. 4,768,411 is disclosed a thermoplastic film bag having tear propagation cuts in the outer edges of the bag seam seals. These cuts allow for the easy tearing open of the bag.
U.S. Pat. No. 4,755,403 discloses a thermoplastic heat shrinkable bag having a protective patch to reduce the likelihood of the bag being punctured or ruptured by the bag contents. The protective patches are heat shrinkable and therefore have a lesser tendency to delaminate when the bag they are adhesively attached to are heat shrunk around the contained product.